The pursuit of ensuring high quality product yield within the semiconductor manufacturing industry is an ongoing endeavor. To that end, the industry expends significant amounts of time and money to methodically test as many completed semiconductor devices as possible to ensure consistent operability. One way in which they accomplish these tests is by the use of a wafer probing apparatus. These wafer probes typically include a prober/tester that is used in conjunction with a separate probe card. The probe card, which is a printed circuit board (PCB), has contact pads on a surface that are engaged by pogo pins of the tester. The probe card includes a ring assembly and probing needles that engage contact pads on a semiconductor chip that is to be tested. The probing needles are mechanically connected to the contact pads. Thus, when the pogo pins engage the contact pads of the probe card, electrical current can be applied to different contact pads of the semiconductor chip to test different areas of the chip to ensure its full operability.
Wafer probe apparatuses do have problems associated with their use. One problematic area involves the very thin probe needles that engage the contact pads of the semiconductor chip. Due to the fact that they are extremely thin (about 76.2 microns or less), they are highly susceptible to alignment issues between the probe card and wafer probe pads associated with high temperature wafer testing. If the needle changes too much in response to a temperature change, it can become misaligned. This can have serious repercussions on the accuracy of the readings, or it can cause the needle to over scrub the semiconductor chip, which can result in irreparable damage to the chip.
Temperature variations can also be introduced during the testing process or when the needle is cleaned during the operation of probing of the semiconductor chips. In such instances, misalignment may occur. To compensate for this, additional testing time must be taken to allow the needle to re-adjust to the temperature change. Sometimes the needle properly re-aligns, and sometimes it does not. This adds additional time to an already lengthy testing process, which further decreases product output productivity. Moreover, any chips that are damaged due to over scrubbing by the probe needles have to be discarded, thereby decreasing product yields as well.
Accordingly, what is needed is an apparatus and method of testing semiconductor devices that avoids the disadvantages associated with the above-described testing devices.